ISSN : 3059-0604
In this paper we show that spheres in <TEX>$E^3{\subset}L^n$</TEX> and pseudohyperbolic spaces in <TEX>$L^3{\subset}L^n$</TEX> are the only totally umbilic spacelike surfaces of type (I) in <TEX>$L^n$</TEX>.
(1979). . Trans. Amer. Math. Soc., 252, 367-392.
(1979). . Tsukuba J. Math., 3(2), 17-29.
(1980). . Memoires Amer. Math. Soc., 28.